1. Field of the Invention
The present invention is directed to a micromechanical structure.
2. Description of Related Art
Such micromechanical structures are generally known. For example, a yaw rate sensor having Coriolis elements is known from published German patent application document DE 102 37 410 A1, the Coriolis elements being excited to vibrations parallel to a first axis with the aid of drive structures, and deflections of the Coriolis elements due to Coriolis forces acting on the Coriolis elements perpendicularly to the first axis being detected by detection structures. The drive structures and detection structures include micromechanical structures, the drive structures being designed in the form of comb Structures. The comb structures include a fixed comb and a movable comb which are situated essentially in the same plane, parallel to the substrate. The fixed comb and the movable comb each have multiple finger electrodes which interlock parallel to a drive direction. The drive force parallel to the drive direction has an inverse dependency on the distances between the finger electrodes of the movable comb and the finger electrodes of the fixed comb. The possible minimum distance is limited by the micromechanical manufacturing process, which has a lower structuring limit. In addition, the micromechanical manufacturing process has a variation in the manufacture of the micromechanical structure, as the result of which the distance between the finger electrodes varies within certain limits. Furthermore, the micromechanical structure has an asymmetry since that much more space is available above than below the drive structures. As a result, the drive structure exerts on the seismic mass not only a drive force parallel to the substrate, but also a so-called levitation force perpendicular to the substrate. As a result, the seismic mass undergoes a so-called levitation motion perpendicular to the substrate which is undesirably superimposed on the detection motion caused by the Coriolis forces.